Direct fuel injection-type spark-ignition internal combustion engine

Abstract

A direct fuel injection-type spark-ignition internal combustion engine is disclosed. The engine comprises a spark plug, a fuel injector and a cavity formed on the top surface of the piston. The cavity has a bottom wall, a spark plug side wall and a fuel injector side wall. The fuel injector injects fuel toward the bottom wall of the cavity in stratified charge combustion. The fuel mainly proceeds toward the spark plug side wall of the cavity along the bottom wall, is deflected by the spark plug side wall and is led to the vicinity of the spark plug. In the engine, the fuel injector side wall of the cavity is provided with a deflecting portion. If a part of the injected fuel proceeds toward the fuel injector side wall along the bottom wall of the cavity, that part of the fuel is led to the vicinity of the spark plug by the deflecting portion.

What is claimed is:  
     
       1. A direct fuel injection-type spark-ignition internal combustion engine comprising a spark plug, a fuel injector and a cavity formed on the top surface of the piston, said cavity having a bottom wall, a spark plug side wall and a fuel injector side wall, said fuel injector injecting fuel toward said bottom wall of said cavity in stratified charge combustion, said fuel mainly proceeding toward said spark plug side wall of said cavity along said bottom wall, being deflected by said spark plug side wall and being led to the vicinity of said spark plug, wherein said fuel injector side wall of said cavity is provided with a deflecting portion, and if a part of the injected fuel proceeds toward said fuel injector side wall along said bottom wall of said cavity, said part of the fuel is led to the vicinity of said spark plug by said deflecting portion. 
     
     
       2. A direct fuel injection-type spark-ignition internal combustion engine according to claim  1 , wherein the injection hole of said fuel injector is positioned on the outer side of an extended plane of said deflecting portion near said injection hole of said fuel injector without contacting said extended plane at a piston position in the latter half of the compression stroke. 
     
     
       3. A direct fuel injection-type spark-ignition internal combustion engine according to claim  1 , wherein said fuel injector injects fuel in the shape of a flat fan having a relatively small thickness. 
     
     
       4. A direct fuel injection-type spark-ignition internal combustion engine according to claim  1 , wherein said spark plug side wall of said cavity has an arcuate portion in a plan view, and a distance from the injection hole of said fuel injector to said spark plug side wall in a plan view is larger than the radius of said arcuate portion. 
     
     
       5. A direct fuel injection-type spark-ignition internal combustion engine according to claim  3 , wherein said fuel injector side wall of said cavity has an arcuate portion in a plan view, and a distance from the center of the contained angle of said fan shape of fuel proceeding toward said fuel injector side wall along said bottom wall of said cavity to said fuel injector side wall is larger than the radius of said arcuate portion.